Yogis in India have long been reputed to develop a remarkable
control over bodily functions. Theoretically, it is believed that
all visceral functions can be brought under voluntary control
by prolonged yogic training, but perhaps their most fascinating
claim has been the ability to stop the heart at will. However,
in most instances where this has been investigated so far, it
has turned out to be an exaggerated Valsalva manoeuvre in some
form, which makes the pulse and heart sounds imperceptible while
the heart continues to beat at a slow rate.

Recently we had the rare opportunity of investigation of an altogether
different and very interesting demonstration of this supposed
yogic control over the heart. Yogi Satyamurti, a sparsely built
man of about 60 years of age, remained confined in a small underground
pit for 8 days in what according to him was a state of "Samadhi",
or deep meditation, with all bodily activity cut down to the barest
minimum. The pit was a 1.5 metre cube, dug out in an open lawn
surrounded by the Medical Institute buildings, and was completely
sealed from the top by bricks and cement mortar. The Yogi squatted
on the floor of the pit with nothing on excepted a light cotton
garment. About 5 litres of water was placed in the corner, presumably
for drinking but according to the Yogi only for keeping the air
humid. An ECG (Lead II) was continuously monitored during these
8 days and various other laboratory investigations were carried
out before and after. The ECG leads were kept short enough not
to allow any free movement inside the pit.

The 12-lead ECG recorded before closing the pit was within normal
limits (Fig. 1, strip A), but a significant sinus tachycardia
developed soon after. It increased progressively, reaching a heart
rate of 250 per minute on the second day (Fig.1,strip B). At 5:15
pm on the second day, when the yogi had been inside for about
29 hours, to our great surprise a straight line replaced the ECG
tracing (Fig.1, strip C). There was no electrical disturbance
of any sort even at higher amplification and with different leads.
There had been no slowing of the heart or signs of ischaemia preceding
this.

The straight line on the ECG persisted till the eighth morning.
Then, to our astonishment, electrical activity returned about
half an hour before the pit was scheduled to be opened. After
some initial disturbance, a normal configuration appeared. Although
some sinus tachycardia was still there, there was no other significant
abnormality (Fig.1, strip D). The Yogi had informed us beforehand
that he would begin to come out of his deep trance or suspended
animation after nearly 7 days, much in the same way that a normal
person wakes up after a few hours sleep.

When the pit was opened on the eighth day, the Yogi was found
sitting in the same posture. One of us immediately went to examine
him. He was in a stuporous condition and was very cold (oral temperaturewas
34.8°C). On being taken out of the pit he developed severe shivering
and this persisted for nearly 2 hours. A 12-lead ECG repeated
in the laboratory subsequently was again within normal limits
(Fig.1, strip E).

The Yogi and his admirers felt more satisfied at his scientifically
documented proof of a remarkable Yogic feat, while we were left
rather perplexed and confused. We were expecting some bradycardia
and possible sign of myocardia ischaemia, but contrary to this
there was severe tachycardia followed by a complete disappearance
of all complexes. Any instrumental failure was ruled out by thoroughly
checking the machine and also by the spontaneous reappearance
of the ECG on the last day. A disconnection of the leads by the
Yogi, quite a likely explanation, ought to have given rise to
a considerable electrical disturbance, but there was hardly any.
Later on, we tried all sorts of manipulations with leads to stimulate
what the Yogi could have done inside the pit (notwithstanding
the total darkness and his ignorance of ECG technique), but in
every case there was marked disturbance. Therefore, although it
is obviously difficult to believe that the Yogi could have completely
stopped his heart or decreased its electrical activity below a
recordable level, we still had no satisfactory explanation for
the ECG tracings before us.

Apart from this, the Yogi had of course endured total starvation,
sensory deprivation, as well as the discomfort of a very humid,
closed atmosphere for 8 days. We did not pay much attention to
anoxia, thinking that sufficient ventilation could occur through
the bare earth on the side of the pit. The loss of weight (4.5
kilograms) and other biochemical changes were essentially the
same as can be expected in starvation under similar conditions.
They certainly discount any remarkable depression of the metabolic
rate.

The more optimistic amongst us considered this feat to be a marvellous
extension of the "hypometabolic wakeful state of yogic meditation"
as described by Wallace and co-workers, and the conditioned learning
of autonomic responses in rats reported by DiCara. The sceptics,
however, were inclined to take the whole thing as some cleverly
disguised trick. But, for the present, we only want to put this
interesting experiment on record just as an intriguing and inclusive
attempt of a Yogi to demonstrate a voluntary control over his
heart beat.